None of the provided options accurately define mechanical force. Mechanical force is generally understood as any push or pull acting on an object, resulting from interactions between objects. It can be quantified through Newton's laws of motion, commonly expressed using the formula \( F = ma \), where \( F \) is force, \( m \) is mass, and \( a \) is acceleration.
Among the provided responses, the closest match describing a related concept is "the product of the mass of an object and gravitational acceleration," but that specifically defines weight rather than mechanical force in general.